1. Field of the Invention
Embodiments of the specification generally relate to a positioning system, and more particularly to a high precision positioning system.
2. Description of the Related Art
Global positioning system (GPS) receivers typically use data from four or more orbiting GPS satellites to determine navigational information such as position and velocity. GPS satellites use relatively low power radio transmitters. For example, a typical GPS satellite may only be rated to 50 W. A typical orbit of a GPS satellite is approximately 14,500 miles above Earth. At that distance, the signal strength of a GPS signal on Earth may be as low as −160 dBW. Since the GPS signals are relatively weak, receiving GPS signals indoors may be difficult since weak signals may not be able to completely penetrate the roof and walls of buildings, increasing the difficultly of determining a relatively accurate position.
Outdoors, with an unobstructed view of the sky, commercial GPS receivers can generally resolve a position to an accuracy of between five to ten meters. Relatively higher resolution (i.e., resolving a position to an accuracy of much less than one meter) may not be possible with commercial GPS receivers. Moreover, resolving the position of a partially occluded GPS receiver, such as a GPS receiver located indoors may not be possible without the aid of GPS pseudolites.
Therefore, what is needed in the art is a method for determining a relatively accurate position in an environment with diminished GPS signal reception.